Effects of vitamin D (VD3) supplementation on the brain mitochondrial function of male rats, in the 6-OHDA-induced model of Parkinson's disease.

Mitochondria dysfunction is an important factor involved in PD pathogenesis. We reported neuroprotective actions of vitamin D (VD3) on a PD model, and now we investigated the VD3 effects on the brain mitochondrial function. We focused on oxygen consumption, respiratory control ratio (RCR), ADP/O ratio, mitochondria swelling, H2O2 production, and SOD activity. Additionally, immunohistochemistry assays for the dopamine system markers (TH and DAT) and mitochondrial markers (VDAC1 and Hsp60) were also carried out in the striata. Young adult male Wistar rats (250 g, 2.5 months age) were anesthetized and subjected to stereotaxic surgery and injection of saline (SO group) or 6-OHDA, into the right striatum. Brain mitochondria were isolated from the groups: sham-operated (SO), 6-OHDA, 6-OHDA pretreated with VD3 for 7, days before the 6-OHDA lesion (6-OHDA+VD3, pre-) or treated with VD3 for 14 days, after the 6-OHDA lesion (6-OHDA+VD3, post-). VD3 prevented decreases in oxygen consumption, RCR, and ADP/O ratio observed after 6-OHDA injury. Noteworthy, a very low (oxygen consumption and RCR) or no improvement (ADP/O) were observed in the 6-OHDA+VD3 post- group. VD3 also prevented the increased mitochondria swelling and H2O2 production and a decrease in SOD activity, respectively, in the 6-OHDA injured mitochondria. Also, VD3 supplementation protected the hemiparkinsonian brain from decreases in TH and DAT expressions and decreased the upregulation of mitochondrial markers, as VDAC 1 and Hsp60. In conclusion, VD3 showed neuroprotective actions on brain mitochondria injured by 6-OHDA and should stimulate translational studies focusing on its use as a therapeutic strategy for the treatment of neurodegenerative diseases as PD.

A Proline Derivative-Enriched Fraction from Sideroxylon obtusifolium Protects the Hippocampus from Intracerebroventricular Pilocarpine-Induced Injury Associated with Status Epilepticus in Mice.

The N-methyl-(2S,4R)-trans-4-hydroxy-l-proline-enriched fraction (NMP) from Sideroxylon obtusifolium was evaluated as a neuroprotective agent in the intracerebroventricular (icv) pilocarpine (Pilo) model. To this aim, male mice were subdivided into sham (SO, vehicle), Pilo (300 µg/1 µL icv, followed by the vehicle per os, po) and NMP-treated groups (Pilo 300 µg/1 µL icv, followed by 100 or 200 mg/kg po). The treatments started one day after the Pilo injection and continued for 15 days. The effects of NMP were assessed by characterizing the preservation of cognitive function in both the Y-maze and object recognition tests. The hippocampal cell viability was evaluated by Nissl staining. Additional markers of damage were studied-the glial fibrillary acidic protein (GFAP) and the ionized calcium-binding adaptor molecule 1 (Iba-1) expression using, respectively, immunofluorescence and western blot analyses. We also performed molecular docking experiments revealing that NMP binds to the γ-aminobutyric acid (GABA) transporter 1 (GAT1). GAT1 expression in the hippocampus was also characterized. Pilo induced cognitive deficits, cell damage, increased GFAP, Iba-1, and GAT1 expression in the hippocampus. These alterations were prevented, especially by the higher NMP dose. These data highlight NMP as a promising candidate for the protection of the hippocampus, as shown by the icv Pilo model.

Vitamin D (VD3) antioxidative and anti-inflammatory activities: Peripheral and central effects.

Vitamin D (VD3, cholecalciferol), besides its role on bone calcium homeostasis, has also been shown to present anti-inflammatory actions. The objectives of the present work were to further extend these findings, focusing onVD3action mechanisms at the molecular level and onits central and peripheral effects. For that, VD3 antinociceptive and mainly anti-inflammatory activities were evaluated by acute models of nociception (formalin test) and inflammation (carrageenan-induced paw edema), in mice pretreated orally for 7 days with VD3 (0.5 and 1.0 mg/kg). Afterwards, the edematous paws were evaluated by immunohistochemical assays for TNF-alpha. In addition, brains from mice pretreated with VD3, at the same conditions, were harvested for iNOS andCOX-2 immunohistochemical (IHC) assays. The anti-inflammatory effect of VD3 on human neutrophil degranulation was evaluated by the release of myeloperoxidase (MPO) activity, as well as by the reactive oxygen species production. VD3 significantly reduced the licking time in the formalin test, at the second phase (inflammatory pain). VD3 also reduced the edema volume and the number of polymorphonuclear (PMN) cells, as well as the TNF-alpha expression in the edematous paws, compared with the control group. Furthermore, VD3 significantly decreased iNOS and COX-2 expressions in brain areas, such as hippocampus and prefrontal cortex, and inhibited the degranulation of activated neutrophils by the reduction of ROS production and MPO release. Based in these results, VD3 presents anti-inflammatory and antioxidative effects, manifested at peripheral and central sites as showed in the present work for the first time.